The present invention relates to image processing and in particular to a method of automatically selecting colours and providing automated colour advice for graphics design applications.
Good colour combination is a desirable feature of graphics design. Positioning text or clip art within an image or printing an image on a coloured background are examples where an artist may be employed to select aesthetically pleasing colour combinations. However, the selection of aesthetically pleasing colour combinations is performed manually, and is often a relatively subjective process.
In content-based image retrieval systems, a popular method of extracting image colour content is to use histograms. To reduce storage required and increase speed, the dimensions of colour histograms are reduced by using some quantisation technique which operates in a perceptually uniform colour space. After histogram dimension reduction, a fixed number of colour bins are used for storing colours. The greater the number of colour bins used, the better quality the reconstructed image has and the greater the storage required.
Unfortunately, using fixed colour bins, the colours of any image can only be represented by fixed colour regions, because known colour extraction systems do not adapt to individual images or the amount of storage available on a system.
Recently, with a growing number of images and video clips available, both on the internet and for personal computers, there is perceived to be a need for an automated colour adviser for use by amateur and professional manipulators of graphic images.
In accordance with a first aspect of the present invention, there is provided a method of determining image representative colours for an image comprising a plurality of image elements having colour information associated therewith, the method including the steps of:
grouping the image elements into a plurality of image element groups on the basis of colours of the image elements;
generating an initial representative colour for each of the image element groups;
clustering the initial representative colours together into colour clusters in a colour space; and
determining an image representative colour based on each respective colour cluster.
In accordance with a second aspect, there is provided a method of providing one or more aesthetic colour suggestions for a given image comprising a plurality of image elements having colours associated therewith, the method including the steps of:
extracting image representative colour information from the image based on the colours of the image elements;
providing a set of colour selection rules.